Understanding the Differences Between COVID-19 and the Common Cold
A sore throat, stuffy nose, cough and fatigue can leave you asking the same question millions of Americans face every respiratory-virus season:
Is it COVID-19, the flu, or just a common cold?
Unfortunately, symptoms alone often cannot give you a reliable answer.
COVID-19, influenza and the common cold are caused by different viruses, but they share many of the same symptoms. That overlap has become even more noticeable as COVID-19 symptoms have changed over time and can sometimes feel very similar to an ordinary cold.
A runny nose and sneezing may point more toward a cold, while sudden fever, chills and strong body aches are more typical of flu. COVID-19 can look like either one. The only reliable way to distinguish COVID-19 from flu in many cases is testing.
COVID vs. Cold vs. Flu: What's the Difference?
All three are respiratory illnesses, but they are caused by different viruses.
- COVID-19 is caused by SARS-CoV-2.
- Influenza is caused by influenza viruses, primarily influenza A and B.
- The common cold can be caused by many different viruses, including rhinoviruses and common human coronaviruses.
Because these viruses affect the respiratory tract, their symptoms frequently overlap.
COVID vs. Cold vs. Flu Symptoms at a Glance
| Symptom | COVID-19 | Flu | Common Cold |
|---|---|---|---|
| Fever or chills | Common | Common | Less common / usually mild |
| Cough | Common | Common | Common |
| Sore throat | Common | Possible | Common |
| Runny or stuffy nose | Common | Possible | Very common |
| Sneezing | Possible | Less typical | Very common |
| Body aches | Possible | Common, often significant | Usually mild |
| Fatigue | Common | Common | Sometimes |
| Headache | Possible | Common | Sometimes |
| Loss of taste or smell | Possible | Uncommon | Usually related to congestion |
| Nausea, vomiting or diarrhea | Possible | Possible, especially in children | Uncommon |
Symptom patterns vary from person to person. This table can provide clues, but it cannot diagnose the cause of your illness.
What Does a Common Cold Usually Feel Like?
The common cold tends to affect the nose and throat more than the rest of the body.
According to the CDC, common cold symptoms can include:
- Runny nose
- Nasal congestion
- Sneezing
- Sore throat
- Cough
- Headache
- Mild body aches
- Occasionally a low-grade fever
Symptoms often peak within the first few days, and many uncomplicated colds improve in less than a week.
Adults in the United States average roughly two to three colds per year, while children often experience more.
What Does the Flu Usually Feel Like?
Influenza tends to hit harder than a typical cold.
A person may feel relatively normal and then develop significant symptoms over a short period.
Common flu symptoms include:
- Fever or chills
- Cough
- Strong muscle or body aches
- Headache
- Fatigue
- Sore throat
- Runny or stuffy nose
Not everyone with influenza develops a fever.
Vomiting and diarrhea can occur as well, particularly in children.
What Does COVID-19 Feel Like Now?
COVID-19 can cause a surprisingly wide range of symptoms.
Current CDC guidance lists possible symptoms such as:
- Fever or chills
- Cough
- Sore throat
- Congestion or runny nose
- Shortness of breath
- Fatigue
- Muscle or body aches
- Headache
- Nausea or vomiting
- Diarrhea
- Loss or change in taste or smell
For many people, especially those with some immunity from vaccination or prior infection, COVID-19 may initially feel like a cold.
That makes testing more useful than trying to identify COVID based on one particular symptom.
Is Loss of Taste or Smell Still a Sign of COVID?
Yes, but it is not as useful as a stand-alone diagnostic clue as it appeared to be earlier in the pandemic.
A new change or loss of taste or smell remains on the CDC's list of possible COVID-19 symptoms.
However, many people with COVID do not experience it.
Colds can also temporarily affect smell or taste when nasal congestion blocks airflow.
Can You Tell COVID From the Flu by Symptom Order?
No.
You may see charts online claiming that COVID always begins with a fever while influenza always begins with a cough or body aches.
Real infections are not that predictable.
The CDC states that you cannot reliably tell COVID-19 and influenza apart based on symptoms alone because many of their symptoms overlap.
Symptoms can appear in different orders depending on the person, immunity, virus strain and severity of infection.
Testing is much more useful than relying on a symptom-sequence chart.
COVID vs. Flu: Which One Starts Faster?
Influenza is known for its relatively sudden onset.
A person may rapidly develop fatigue, fever, chills and muscle aches.
COVID can also begin quickly, but its timing is more variable.
CDC information indicates that flu symptoms commonly appear about 1 to 4 days after infection, while COVID symptoms have historically been observed within a broader window.
The exact incubation period for COVID can vary as SARS-CoV-2 continues to evolve.
Should You Test for COVID or Flu?
Testing can be particularly useful if your symptoms could represent COVID-19 or influenza.
This matters even more when you:
- Are older
- Have a chronic health condition
- Have a weakened immune system
- Are pregnant
- Are at increased risk of severe respiratory illness
- Live with someone who is medically vulnerable
Why?
Because treatments for both COVID-19 and flu are most useful when started early.
At-Home COVID and Flu Combination Tests
Testing has become easier in the United States.
At-home combination tests can detect SARS-CoV-2 along with influenza A and B from a nasal swab.
In 2024, the FDA granted traditional marketing authorization to the first over-the-counter home test designed to detect both COVID-19 and influenza without a prescription.
Additional home combination tests may also be available under FDA authorization.
These tests can be especially convenient during respiratory-virus season when symptoms overlap.
What If Your COVID Home Test Is Negative?
One negative antigen test does not always rule out COVID-19.
The FDA advises following the repeat-testing instructions that come with the test because testing too early in an infection can produce a false-negative result.
If you remain symptomatic or have a high-risk exposure, repeat testing or a more sensitive laboratory test may be appropriate.
COVID Treatment: Why Early Testing Can Matter
Most people with mild COVID-19 recover at home with supportive care.
However, people at higher risk for severe disease may qualify for antiviral treatment.
Current U.S. outpatient treatment options can include:
- Paxlovid (nirmatrelvir with ritonavir)
- Remdesivir (Veklury)
- Molnupiravir (Lagevrio) in selected situations
Timing matters.
CDC guidance states that COVID treatment for eligible higher-risk patients generally needs to begin within 5 to 7 days after symptoms start, depending on the medication.
Contact a healthcare professional promptly after symptoms begin. Waiting several days to “see if it gets worse” can cause you to miss the treatment window.
Flu Treatment: Antivirals Work Best Early
Prescription flu antivirals can make influenza symptoms milder and may shorten the duration of illness.
Common options include:
- Oseltamivir (Tamiflu)
- Zanamivir (Relenza)
- Peramivir (Rapivab)
- Baloxavir (Xofluza)
CDC guidance says these medications generally work best when started within 1 to 2 days after flu symptoms begin.
For people who are hospitalized, seriously ill or at high risk for complications, treatment may still be recommended even when more time has passed.
Do Antibiotics Help COVID, Flu or a Cold?
No.
Antibiotics treat bacterial infections. COVID-19, influenza and most common colds are caused by viruses.
Taking an antibiotic for an uncomplicated viral infection will not make the virus disappear faster.
It can also cause side effects and contribute to antibiotic resistance.
Antibiotics may be appropriate only when a healthcare professional determines that a secondary bacterial infection has developed.
How to Treat a Common Cold at Home
There is no cure for the common cold, but most cases improve on their own.
Helpful measures may include:
- Rest
- Drinking enough fluids
- Using a humidifier when indoor air is dry
- Saline nasal spray or drops
- Honey for cough in adults and children over age 1
- Appropriate over-the-counter pain or fever medication
Always follow medication labels carefully, especially when giving cold medicine to children.
How Long Do These Illnesses Last?
Common Cold
Many colds improve within a week, although cough or congestion can occasionally linger longer.
Influenza
Many people recover within several days to about two weeks. Fatigue or cough can persist after the worst symptoms improve.
COVID-19
COVID recovery varies considerably. Some people feel better after several days, while others have symptoms for longer.
A subset of people can develop persistent health problems known as Long COVID, even after an initially mild infection.
How Long Should You Stay Home When You're Sick?
Current U.S. respiratory-virus guidance focuses more on how you feel than on a single fixed isolation period for everyone.
If you are sick with a respiratory illness, stay home and away from other people while you are ill.
After returning to normal activities, additional precautions can help reduce transmission, especially around people at higher risk.
These may include:
- Wearing a well-fitting mask
- Improving indoor ventilation
- Keeping some distance from vulnerable people
- Practicing good hand hygiene
- Testing when appropriate
Do Masks Still Help Prevent Respiratory Viruses?
Yes.
Masks can provide an additional layer of protection from respiratory infections.
They are particularly useful when:
- Respiratory illness levels are high in your community
- You are sick or recently exposed
- You are recovering from an illness
- You will be around someone at higher risk
- You are in a crowded indoor setting
Fit and filtration matter.
Well-fitting respirators such as N95s generally provide more protection than loose-fitting cloth masks.
Ventilation Matters More Than Many People Realize
Respiratory viruses can spread through infectious particles in indoor air.
Improving indoor air quality can reduce exposure.
Simple strategies include:
- Opening windows when practical
- Using exhaust fans
- Running HVAC systems appropriately
- Using suitable air filtration
- Spending more time outdoors when conditions allow
Vaccination Still Matters
Vaccination remains one of the most important tools for lowering the risk of severe respiratory illness.
Seasonal influenza vaccination and recommended COVID-19 vaccination can reduce the risk of severe disease, hospitalization and death.
Because U.S. vaccine recommendations can change by age, risk factors and season, check the latest CDC schedule or ask your healthcare provider which vaccines are recommended for you.
When Should You Call a Doctor?
Contact a healthcare professional promptly if:
- You are at high risk for severe COVID or flu
- Your symptoms are getting progressively worse
- A fever or cough improves and then returns or worsens
- You have significant dehydration
- You have a serious chronic medical condition
- You are concerned about a young child, older adult or immunocompromised family member
Early medical advice is particularly important because antiviral treatment has a limited treatment window.
When Is It an Emergency?
Seek emergency medical care for serious warning signs such as:
- Difficulty breathing or severe shortness of breath
- Persistent pain or pressure in the chest
- New confusion
- Inability to wake or stay awake
- Severe weakness or instability
- Seizures
- Signs of severe dehydration
- Any other symptom that feels severe or rapidly worsening
Do not rely on an online symptom comparison when emergency symptoms are present.
Frequently Asked Questions
How can I tell if I have COVID or a cold?
You often cannot tell with certainty from symptoms alone. Sneezing and nasal congestion may be more typical of a cold, but COVID can cause the same symptoms. Testing is the best way to confirm COVID.
How can I tell if I have flu or COVID?
Symptoms overlap too much for a reliable diagnosis based only on how you feel. A COVID/flu combination test or separate diagnostic tests can identify the virus.
Is a runny nose more likely COVID or a cold?
A runny nose is extremely common with a cold, but it is also a recognized COVID symptom. It cannot rule COVID in or out.
Does the flu always cause a high fever?
No. Fever is common with influenza, but some people with the flu never develop one.
Can you have COVID and flu at the same time?
Yes. Coinfection is possible, although it is less common than having either infection alone. People can also have other respiratory viruses at the same time.
Should I test if I think it's just a cold?
Testing becomes more important if you are at higher risk for severe illness, have been exposed to COVID or flu, live with vulnerable people, or might qualify for antiviral treatment.
Can COVID feel like allergies?
It can. Nasal congestion, runny nose and sore throat can overlap. Allergies are more likely to cause itchy eyes and repeated sneezing and usually do not cause fever or significant body aches.
Can COVID or flu be treated with antibiotics?
No. Both are viral infections. Antibiotics are used only when a bacterial infection is also present.
The Bottom Line
The days when COVID-19 could easily be identified by one distinctive symptom are largely gone.
A sore throat, cough, congestion and fatigue might represent COVID-19, influenza, a common cold or another respiratory virus.
Instead of trying to diagnose yourself by the order in which symptoms appear, focus on what actually changes your next step:
- How sick are you?
- Are you at higher risk for complications?
- Could testing change your treatment?
- Are you protecting people around you?
For otherwise healthy people with mild symptoms, rest and supportive care may be enough.
For people at higher risk, however, early testing and prompt treatment can matter because both COVID-19 and influenza have antiviral treatments that work best when started soon after symptoms begin.
